Human actions on Earth are altering the natural greenhouse effect. The use of fossil fuels such as coal and oil has raised the concentration of carbon dioxide in the atmosphere during the last century (CO2). This occurs as a result of the coal or oil burning process, which mixes carbon with oxygen in the air to produce CO2. Other factors such as deforestation and soil degradation contribute to this change.
There are several ways that humans are altering the natural carbon cycle and thus the amount of CO2 in the atmosphere:
Burning fossil fuels for energy production is the main source of CO2 emissions today. The combustion process removes carbon from the earth's surface and stores it in the form of CO2 in the human-made reservoirs of fuel oil and natural gas. If all fossil fuels were extracted and burned, the amount of CO2 in the atmosphere would rise by about 50 percent.
Deforestation and soil degradation are other major sources of CO2 emissions. Trees take up carbon from the atmosphere when they grow large enough. They release this carbon when they decay or are burned. Deforestation means that trees are removed from their land and used for other purposes - often for farming - resulting in less vegetation growth and therefore more CO2 released into the atmosphere. Soil degradation is caused by changes to the physical nature of the soil that make it easier for organic material to be removed when plants die or are harvested.
The principal sources of rising carbon dioxide concentrations in the atmosphere are human activities such as the combustion of oil, coal, and gas, as well as deforestation. Land surfaces are also a source during periods of drought when water vapor is lost to the atmosphere.
CO2 is a greenhouse gas. When it stays in the atmosphere long enough, it causes temperatures to rise. This is why scientists are so concerned about how much CO2 ends up in the atmosphere. The more there is, the hotter it will get. We already know this is a problem because we've seen recent changes in climate that have been linked to increased CO2 levels.
In conclusion, human activities are responsible for most of the CO2 released into the atmosphere, which leads to global warming.
What human activities contribute to the rise of carbon dioxide in the atmosphere?
Increasing levels of carbon dioxide and other gases amplify the planet's natural "greenhouse effect." Prior to the Industrial Revolution in the late 1800s, CO2 levels were approximately 280 parts per million, when huge volumes of greenhouse gases began to be emitted by burning fossil fuels. Since then, CO2 levels have increased to about 400 ppm.
How has increasing CO2 affected the climate? Scientists are still debating exactly how much of an impact CO2 has had on global warming over the past 200 years, but it is clear that our atmosphere contains more than enough carbon dioxide today to have an enormous impact on Earth's climate.
Scientists predict that if CO2 emissions continue to increase at their current rate, then by 2100 there will be more than double what today is expected to be the case with respect to CO2 in the atmosphere. Some scientists believe that this could lead to temperatures rising by as much as 10 degrees Celsius (18 degrees Fahrenheit). However, others think that we will be able to adapt to such changes or perhaps even benefit from them.
Does Antarctica show evidence of recent climate change? Yes. Ice cores taken from Antarctica reveal that large amounts of carbon dioxide were released into the atmosphere after the advent of agriculture, when fossil fuel use for heating and cooking became common. The ice cores also show that during times of drought, plants use up the carbon they have stored in their roots for growth.
Carbon dioxide concentrations are growing mostly as a result of people's usage of fossil fuels for energy. Carbon dioxide emissions come from electricity generation, transportation, and industry. The main source is the burning of fossil fuels such as oil and natural gas that release carbon dioxide into the atmosphere.
Electricity generates most of its CO2 emissions during production - about 40% - with the rest coming from transport operations and building heating/cooling. Transportation emissions can be reduced by using more renewable energy sources such as solar or wind power but this doesn't reduce global warming pollution as much as reducing emissions from gasoline or diesel vehicles. Producing electricity from natural gas also releases CO2 into the atmosphere because it takes fossil fuels to extract, process, and burn them.
The amount of CO2 in the atmosphere has increased from about 280 parts per million (ppm) in 1750 to 400 ppm today. The main cause of this rise is the use of fossil fuels which produce CO2 when burned. The second largest source of CO2 is deforestation which reduces the ability of trees to absorb CO2 from the atmosphere.
As we know, CO2 traps heat in the atmosphere, so more CO2 means warmer temperatures.
The combustion of fossil fuels emits chemicals into the atmosphere, lowering forest cover, and the fast expansion of farming, development, and industrial activity emits carbon dioxide into the atmosphere, altering the climate system's equilibrium. This leads to more warming or cooling depending on the gas involved.
Chemical reactions between atmospheric gases and the Earth's surface produce some species that are harmful to humans. Ozone depletion occurs when ultraviolet radiation from the Sun breaks down ozone molecules, allowing UV rays to reach the ground. The result is a increase in the number of toxic substances called free radicals that can damage plant life and animal tissue. Ozone loss has been estimated to have caused around 12 million annual deaths from respiratory diseases during the 20th century.
Greenhouse gases work like glass sheets in a greenhouse. They allow light waves to pass through them, but they also trap heat within the container. So if there are more of these gases in the atmosphere, it gets hotter inside the container. Greenhouses use electric lights instead of sunlight because they reduce the amount of energy required to grow plants artificially. Otherwise, they would need as much energy as a city-sized town!
Electricity and heat production account for about a third of all greenhouse gas emissions, with just under a fifth coming from transportation sources such as cars, trucks, and airplanes. The rest comes from industry and agriculture.